John W. Polanowicz is known as a financially savvy executive who can bring stability to struggling institutions.

Now the turnaround expert has been charged with leading the vast state office of Health and Human Services.

There, too, he is expected to lead — if not a complete turnaround — some big changes.

The office — made up of 22,000 employees and 15 agencies that serve the general public, veterans, people with disabilities and the poor — is reeling from a series of scandals. A chemist is accused of tampering with evidence in a state drug lab, disrupting the criminal justice system. And state regulators have been blamed for lax oversight of a compounding pharmacy in Framingham that was the source of tainted drugs believed to have caused a meningitis outbreak.

Just this week, the state inspector general announced Massachusetts may be overpaying welfare benefits by $25 million a year.

“For better or for worse, we do have a crisis in confidence in the department, and that's something we need to work very hard to recover,” Mr. Polanowicz said.

The new secretary, who lives in Northboro, comes to the governor's cabinet from St. Elizabeth's Medical Center, a 252-bed hospital in Brighton, where he was president and CEO since 2011. Before that, he was president and CEO for eight years at Marlborough Hospital, part of the UMass Memorial Health Care system.

Both hospitals were losing money before Mr. Polanowicz took the top jobs there. He brought stability to both institutions, he said, by building effective leadership teams and reorganizing programs.

Now Mr. Polanowicz, 50, will be a key figure in the implementation of a state law that aims to control health care costs.

In naming him secretary, Gov. Deval L. Patrick said: “John will use his expertise as a health care leader to help Massachusetts increase our already nation-leading access to care, while also tackling the issue of costs.”

Mr. Polanowicz was at the Worcester Recovery Center and Hospital this week, his first big public appearance since being sworn in Jan. 22. He was there to promote the governor's new budget proposal.

All of the 15 agencies in the Executive Office of Health and Human Services, including the Department of Public Health, would see an increase under the governor's budget plan, he said, for purposes as varied as preventing youth violence to expanding dental coverage.

In an interview later, he said improving mental health treatment was one of his priorities. He also plans to focus on controlling health care costs, and improving “program integrity” — or tackling fraud.

Mr. Polanowicz is an Army veteran who graduated from West Point and commanded a Blackhawk helicopter company. He has an MBA from Stanford and worked in management consulting before joining UMass Memorial Health Care. There, he worked his way up to vice president of operations.

UMass Memorial President and CEO John G. O'Brien, who has known Mr. Polanowicz for more than a decade, said his skill set makes him the right pick for HHS secretary. “John has outstanding financial skills, but he also is an incredible humanist,” Mr. O'Brien said.

Mr. Polanowicz is new to the public sector, but his wife, Kathleen, is district director for U.S. Rep. James P. McGovern, D-Worcester.

As secretary, Mr. Polanowicz replaced JudyAnn Bigby, a physician, who resigned in December. Before Dr. Bigby, the health secretary was Timothy R. Murphy, an aide to then-Gov. Mitt Romney, and a former investment banker.

“I'd like to think I'm bringing a level of leadership and an ability to focus on operations,” Mr. Polanowicz said, “to improve systems that we have here in the secretariat and to make sure we're providing them as efficiently and as cost-effectively as we can.”